When Guitar World asked new Guns N' Roses guitarist Gilby Clarke which song in the band's back catalog was the toughest to learn, he answered with no hesitation, "Without a doubt, 'Coma.' I still don't know it. It's like this 15- or 20-minute song with no repeats."

On a pair of albums with no shortage of long, challenging songs, "Coma" stands out as perhaps the most challenging and definitely the longest. While the live version could peak at nearly 20 minutes in length, the studio version came in at just over 10, plenty of time for Axl, Slash and Co. to pack in everything but the kitchen sink — and that includes a defibrillator.

As Gilby implied, "Coma" lacks any semblance of a definable chorus, all the more fitting for a song that sees the band taking listeners on a visceral journey through the mind of a coma patient.

Oh, and when we asked Gilby what his favorite Guns N' Roses song to play was, he said, "Oddly enough, 'Coma.' I really love playing it because it's different every time."